(1) Fields of Industrial Utilization
The present invention relates to a method of surface treatment of members used with water and/or oil, and grease etc., surface treatment agents, surface treated members, surface treated bodies, and apparatus mounted with same.
(2) Description of the Prior Art
Water, oil, and grease are used in many products. One of the objects using water is cooling. As concrete products, there are a radiator of a car, and a water cooled type large scale computer etc. But, there are many members which will cause troubles with water around water cooled portion of the above described products, and when water leaks from the water cooled portion, there is a possibility to cause a serious damage. And, using objects of oil and grease spread to various field such as lubrication, sealing, and corrosion protection etc. Concretely saying, lubrication of a bearing, heat conductor for cooling of heat generated in an apparatus, and sealing material such as packing etc. can be enumerated. Oil and grease are indispensable for a bearing as a lubricant. On the other hand, as water, oil, and grease seep out from the bearing after using for a long time, sufficient water, oil, and grease are not supplied to the rubbing portion, and consequently, sticking is caused and stable driving becomes impossible. Accordingly, periodic supply of lubricants and prevention of seeping out by use of packing are performing. It is present status that reliability of water, oil and greases used as a heat conductor for cooling of heat generated in an apparatus for a long time is not realized yet because of seeping out.
Especially, current electronic apparatus are rapidly developed in down sizing, decreasing weight, high densification, and speed up of response. Accordingly, miniaturizing and high performance of each members composing electronic apparatus are required. Among the electronic apparatus, there are many apparatus which are furnished with members using water, oil and grease, and the members remarkably contribute to the reliability of the apparatus. On the other hand, there are many fine members which cause operation impossibleness and failure when the members are contaminated with dust and insulating material and deficiency of oil at a rotation system and a rubbing portion are generated, and there is a possibility that seeping out and diffusion of water, oil and grease may cause a remarkable damage to the fine members. Actually, various kind of failures such as insulation deficiency and operation impossibleness etc. are induced by leakage and seeping out of grease into other members than the ordinary using members.
A case of a large scale computer as an example of electronic apparatus, thermal flux in the device for the large scale computer is increased in accordance with higher integration. Accordingly, a cooling system having high performance corresponding to the computer with increased heat generation and low cost corresponding to general computers is required.
For realizing the high performance and the low cost, using of grease for heat transfer between cooling portions of the two devices is inevitable at the present.
Correspondingly, a method for cooling a chip effectively by preferable heat transferring between the chip and a cooling portion is proposed.
A cooling element for heat transferring from an integrated circuit or a chip and cooling portion disclosed in JP-B-56-22380 (1981) is the cooling element composed of a block on a cylinder having a curved surface on a semisphere, a housing having similar shaped holes, and an elastic body for binding the block and the housing.
Further, in order to improve heat transfer at contacting boundaries of the cooling element, using of grease to electronic apparatus and integrated circuits are proposed.
In the reference FUJITSU vol. 41, No. 1 pp. 12-19 (1990), grease was used between a chip and a cooling apparatus in order to realize preferable heat transfer at the contacting boundary.
As for issues in using grease, of course, not only superior heat conductivity but also prevention of oil seeping out are important in view of reliability for a long time.
That means, in order to use water, oil, and grease in a stable condition for a long time, certain sealing to the using portion is an extremely important technology.
Correspondingly, methods for surface modification by material containing mainly fluorine as a technique to protect surface of a base plate from water, oil, and grease, and to improve removal of oil and water are proposed. Methods for preventing water, oil, and grease from contaminating surface of bodies by applying fluorine group resin are disclosed in JP-A-63-120789 (1988), JP-A-1-304936 (1989), JP-A-60-31535 (1985), and JP-A-60-259837 (1985). On the other hand, methods for surface modification by fluorinated surfactant and silane coupling agents are disclosed in JP-A-60-190727 (1985), JP-A-62-253045 (1987), JP-A-59-30848 (1984), JP-A-63-35681 (1988). Further, a method for preventing seeping out of grease to the optical lenses by applying a seeping out prohibiting agent containing fluorinated surfactant as a main component is disclosed in JP-A-59-126109 (1984).
The above described prior arts disclosed in JP-A-63-120789 (1988), JP-A-1-304936 (1989), JP-A-60-31535 (1985), JP-A-60-259837 (1985), JP-A-60-190727 (1985), JP-A-62-253045 (1987), JP-A-59-30848 (1984), JP-A-63-35681 (1988), are for protecting surface of a body from water, oil, and grease, and objects of the protection are anti-contamination, lubrication, and corrosion resistance etc. In a case of anti-contamination, when water, oil, and grease adhere to the surface, removal of the water and the oil is facilitated by forming a water repellent and oil repellent compound layer on the surface, and contamination of the surface is prevented. Besides, for lubrication, a water repellent and oil repellent compound layer is formed on the surface for preventing sticking of rubbing surface with other's surface. That means, the prior arts regard water, oil, and grease as materials which externally effect undesirable influence to whole surface of a body or the body itself, and anti-contamination, lubrication, and corrosion resistance are realized by previously forming a water repellent and oil repellent compound layer on the whole surface which contacts with water, oil, and grease.
The prior art disclosed in JP-A-59-126109 (1984) regards existence of grease as inevitable, and seeping out of grease to lenses in an optical system is prevented. But, the technique in the prior art was only applying a simple fluorinated surfactant, and accordingly, as the fluorinated surfactant applied on the flat surface was easily removed by slight rubbing, there was a problem in reliability of the fluorinated surfactant for a long time. In order to overcome the problem, steps are provided to the place where the fluorinated surfactant is applied so as to make the fluorinated surfactant remains on the surface. But, the prior art improving the surface by the fluorinated surfactant can not be applied to flat surface.